The invention is based on a method for determining a thickness of a layer of electromagnetically conductive material, in particular a chromium layer, as described for example in German Patent Disclosure DE-A 196 52 750.3, published after the filing date of the present application. A prerequisite of that measuring method is that the quality of the basic material onto which the layer is applied is relatively constant over production and fluctuates only within narrow limits. In mass production, however, these narrow fluctuation limits can be adhered to only with difficulty. Hence measurement inaccuracies in determining the layer thickness can come about.
The method of the invention for determining a thickness of a layer of electromagnetically conductive material, having the characteristics of the independent claim, has the advantage over the prior art that layer thickness determination is possible when the quality of the basic material fluctuates relatively widely. The resultant measurement errors can be largely eliminated by means of a premeasurement. Particularly in mass production, the base bodies produced by different vendors have different qualities in terms of material properties and thus have different electrical and magnetic properties. These fluctuations in the material nature of the basic material can be eliminated relatively simply.
By means of the provisions recited in the dependent claims, advantageous refinements of and improvements to the method defined by the independent claim are possible.